Aquatic Antibiotic Pollution and the Environmental Dissemination of Antimicrobial Resistance

Antimicrobial resistance (AMR) is one of the greatest public health challenges of the twentyfirst century, threatening the effectiveness of medicines used to treat bacterial, viral, fungal,
and parasitic infections. Although the misuse and overuse of antibiotics in human and
veterinary medicine are well-recognized drivers of AMR, increasing attention is being directed
toward antibiotic pollution in the environment, particularly in aquatic ecosystems. A
considerable proportion of administered antibiotics is excreted unchanged or as active
metabolites, eventually entering wastewater systems, rivers, lakes, and irrigation water. Even
at low concentrations, these antibiotic residues exert selective pressure that promotes the
survival and spread of antibiotic-resistant bacteria (ARB) and antimicrobial resistance genes
(ARGs). These resistant microorganisms can subsequently move through aquatic ecosystems,
food chains, livestock, wildlife, and ultimately to humans, highlighting the interconnected
nature of environmental, animal, and human health. This article discusses the major sources of
antibiotic contamination in water, explains how aquatic environments contribute to the
dissemination of antimicrobial resistance, and summarizes current approaches for detecting
and tracking resistant bacteria and resistance genes. Reducing antibiotic pollution through
responsible antimicrobial use, improved wastewater management, environmental surveillance,
and public awareness will be essential to slowing the global spread of antimicrobial resistance.